The present invention relates to an apparatus and method for an electronic locking system. The system encompasses both a signal transmitting unit and a signal receiving unit for an electronically controlled and electromagnetically actuated locking system to replace the use of mechanical keys and mechanically controlled code locks such as combination locks. This invention recognizes that cost effective electronic and elecromagnetic components can be combined to make a locking system with reliability that exceeds that of purely mechanical locking devices. In addition, the storage of coded key information in a digital format within a portable solid state memory, which may be incorporated in a wrist watch or some similar device, is more convenient than actually carrying a set of keys. This locking system has universal application in home, business, recreation, defense, etc., wherever locks or codes are used.
Several previous systems are known which, through complexity of operation or bulk of transmitting and receiving units, fail to provide the flexibility and ease of operation of the present electronic locking system. Among the known prior art systems is U.S. Pat. No. 3,024,452 which discloses a multi-digit electric door lock. The system amounts to merely an electrical combination lock in which a plate is provided with a plurality of pushbuttons containing the digits zero through nine. After they are manually preset to a combination which will unlock the door, the pushbuttons may then at any time thereafter be actuated in succession with the three digit number to which they were manually preset so as to unlock the door by causing a solenoid to be temporarily energized.
U.S. Pat. No. 3,029,345 discloses an electronic key card system which requires a card B to be inserted in a slot of a control housing 12. In this system, each of the cards is provided with predetermined portions identified at reference numerals 20 and 21 to transmit light from one side of the control housing to the opposite side of the control housing which contains a photodetector circuit. If the predetermined portions of the control card B allow for the light to be transmitted therethrough, the system will unlatch a door lock controlled by a power source.
U.S. Pat. No. 3,144,761 discloses a lock release system which is operated by infrared radiation. The lock release system is manually operated by the rotation of a drive means 32 which moves a chopper disc which has a predetermined amount of material removed from various sections thereof. When the key device is placed to a window of a safe, the manual drive system 32 is rotated so as to move the chopper disc so that, during the moment, light passes through part of the cutaway disc. The output of the key is, therefore, a steady amount of infrared radiation which is interrupted by pulses. The detector, upon the receipt of a preset sequence of signals, unlocks the latching mechanism and allows entry to the safe. This sytem merely allows a constantly energized source of light to be interrupted by a manually rotated disc so as to sequence the light in a predetermined manner.
U.S. Pat. No. 3,872,435 discloses an opto-electronic security system wherein the key apparatus and the lock apparatus are precoded and which does not include an integral electrical power source. The lock device code is preset during the manufacture by hard wiring the components to transmit only a factory-assembled code.
U.S. Pat. No. 4,143,368 discloses a vehicle operator security system in which the driver of a vehicle carries a portable infrared signal generator which is actuatable to generate, selectively, at least two separate digitally coded infrared signals. The locking mechanism, contained in the vehicle, receives the signals, decodes them and actuates an apparatus in response to the first digital code so as to perform a first function such as unlocking a door to the vehicle. The second digital code is received so as to sound an alarm, upon actuation of the operator, at any time the operator perceives a reason for actuating the alarm. The transmitter unit of the locking system is provided with preset code storage means which contain a 14 bit identification code for four different switches. The code storage means are permanently contained in the transmitter.
U.S. Pat. No. 4,218,681 discloses a hand-held transmitter of the type that is well known for controlling the remote movement of garage door installations or like systems. The unit is provided with two different electromagnetic frequencies which can be transmitted as signals after a circuit-actuation pushbutton is turned on.
U.S. Pat. No. 4,325,146 discloses a non-synchronous object identification system which utilizes light-emitting diodes and detectors for supplying coded information to and receiving coded pulses from a device carried in the vehicle which is to be identified.
U.S. Pat. Nos. 4,354,189 and 4,189,712 relate to switch and lock activating systems and method. The patents are related as a continuation and contain the same disclosure. The disclosure relates to a system and method for opening a lock or activating a switch by electronically controlled devices. The device utilizes a finger ring which contains a code recording associated with the crown of the ring. Although the use of a watch is shown in conjunction with controlling a lock, it is to be noted that the watch is to be used in conjunction with a coded finger ring and, therefore, the codes, read by the lock actuating mechanism, are transmitted from the coded finger ring and the watch generates an energy field which is activated only when the ring is disposed within a cavity of the lock-actuating mechanism so that the code contained therein can be read.
My earlier U.S. Pat. No. 4,573,046 is directed to an improved electronic locking system which employs an encoded optical signal to control the latching and unlatching of a lock mechanism.